Screw-machine.



PATENTED APR. 30, 1907.

W. H. GATES. SCREW MACHINE. APPLICATION FILED APB.8. 1903.-

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PATENTEDAPR. so, 1907.

W Z 4 1 5 8 m N SCREW MACHINE. APPLIOATION FILED APR. 8. 1903.

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No, 851,742. PATENTED APR; so, 1907. W'. H. GATES.

SCREW MACHINE.

- APPLICATION FILED APR-8. 1903.-

5 SHEETS-SHEET 4.

WILLIAM H. GATES, OF NORWICH, CONNECTICUT.

SCREW-MACHINE.

Specification of Letters Patent.

Patented April 30, 1907.

Application filed April 8, 1903. Serial No. 151,614.

To all 1071,0110 it inlay concern.-

Be it known that 1, WILLIAM H. GATES, a citizen of the United States, residing at Norwich, in the county of New London and State of Connecticut, have invented a new and useful Screw-Machine, of which the following is a specification.

This invention relates especially to that 1 a particular oliject of my invention-is to provide a screw machine of this class in which a solid die may lte employed without requiring a reversal or change of direction of rotation of the machine spindle.

In the accompanying five sheets of drawings, Figure 1 is a plan view of sullicient parts of a screw machine to illustrate the application of my invention thereto. Fig. 2 IS a side view thereof partly in section. Fig. 3 is an enlarged view of part of the head stock spindle. Fig. 4 is an end view of the machine. Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1. Figs. 6 and 7 are detail views of the operating segments for the cutting off-tool carriages. Fig. 8 is a view of the opposite end of the machine from that illustrated in Fig. 4. Fig. 9 is a detail view illustrating the means for operating the locking pin for holding the tool slide in place. Fig. 10 is a detail view of the connections for shifting the tool slide widthwise with respect to the machine. Fig. 11 is a detail view of a segment and the slotted arm which turns therewith, and has a pin which can he set to different positions to vary the advance stroke of the tools. Fig. 12 is an enlarged sectional view of the threading spindle. Figs. 13 and H are detail views showing the pins which hold the die-holder from rotating while cutting a thread, and Fig. 15 is a detail view of the operating finger and pin for turning the spindle of the (lie-holder to hack the die off from a completed screw.

In a screw machine constructed according to this invention the successive operations are all preferably controlled from a cam shaft at the rear of the machine) Secured on this cam shaft are six drums or cam wheels to which cams may be fastened to produce the following operations: 1st, to open and close the clutch and feed new lengths of wire into position; 2nd, to withdrawthe locking pin which fastens the tool slide in position; 3rd, to move the tool slide transversely across the machine to successively bring a series of tools into line with the head stock spindle 4th, to successively advance the tools to shape and thread the shank of the screw; 5th, to decrease the speed of rotation of the main spindle while the die is forming a thread and lzeing backed oil therefrom and to again increase the speed of rotation, but without changing its direction so that the cutting and shaping operations willhe performed at one speed and the threading operation at a lower speed, but the direction of the rotation will not he changed, and 6th, to operate the cutting off tools which cut the completed screws from the rod or wire.

The cam shaft which controls these successive operations is located at the rear of the machine, so that the front of the machine is preferably left entirely unobstructed. The cam wheels or drum on the cam shaft are preferably provided with bolt holes for receiving bolts to adjustably fasten the pieces in place which form the operating cams.

The adjustment of the machine for different kinds of product is accomplished by changing the location or character of the cam-pieces on the cam wheels or drums, with the exception that the operating train for the tools is controlled from an adjustable pin which may be set to different positions, so that a single adjustment will vary the length of operative stroke of all the tools without requiring changes of the operating cams.

A characteristic of a screw machine constructed according to this invention which I regard as of importance is that during the operation of the machine, the head stock spindle has a fixed direction of rotation, and there is never any reversal or change of direction of such rotation. In practice, I have found this to be of advantage for the reason that the time required for reversals is saved, while the mechanism does not wear out so rapidly as when subjected to the strains of reversal or change of direction of motion. A

still further advantage in avoiding all reversals of the direction of rotation of the main spindle is due to the fact that the cutting ofl tools may be set into operation and may be actively cutting through the stock to separate the screw from a rod at the same time that the die is being backed off from the thread.

Referring to the drawings and in detail, as illustrated most clearly in Fig. 2, r. designates 1 the usual bed-plate or trough supported upon legs L. Extending up from the bed-plate or trough A are standards which support the bed or main frame B of the screw machine.- Journaled in the usual head stock bearings is a main spindle 10. Mounted loosely on the head stock spindle is a low speed pulley 1 1 which is driven by belt and is employed for turning the head stock spindle when the die is acting to cut the thread. Also mounted loosely on the head stock spindle 10 is a high speed pulley 12 which is driven by belt at a considerably higher speed than the pulley 11. The high speed pulley 12 is mounted loosely on the head stock spindle 10 and is normally connected to turn the head stock spindle during the cutting and shaping operations and during the greater part of the time that the machine is in use. The pulleys 11 and 12 turn in the same direction, and no reversal or change ofdirection of the rotation of the head stock spindle 10 is required in the operation of the machine. Journaled in bearing at the rear of the machine, as shown in Fig. 1, is the cam shaft 13. The cam shaft 13 is driven from the head stock spindle through a train of gearing illustrated most clearly in Figs. 2 and 4.

As shown in Fig. 2, 14 designates a gear secured on the head stock spindle 10, which gear 14 meshes with and drives a gear 15 secured on a shaft at the opposite end of which is a worm 16 which meshes with and drives a worm wheel 17 upon an inclined shaft, which, as illustrated most clearly in Fig. 4, is journaled in hearings in a pivoted sweep S which may be locked by a nut on a fastening bolt N to hold the worm-wheel 17 in mesh with its worm 1 6.

The sweep S as shown most clearly in Fig. 4, permits the inclined shaft to be dropped down so that interchangeable sets of wormwheels may be employed. At the lower end of the inclined shaft is secured a worm 18, which meshes with and drives a worm-wheel secured on the cam shaft 13.

Any of the ordinary or usual constructions may be employed for feeding the wire or rod v forward through the head stock spindle, and for opening and closing the head stock clutch.

As illustrated in Fig. 1, a cam drum or wheel 20 is secured at one end of the cam shaft 13, and is provided with two series of holes for fastening bolts for fastening two sets of cams or operating pieces thereon.

One set of cams is intended to engage and operate a pin extending from a sliding piece 21 mounted on. a rod or shaft 23. The slide 21 is connected by an arm to a grooved wheel carried by the feed bushing 24.

As illustrated most clearly in F 3, the feed bushing 24 is provided at its opposite end with a detachable split ended piece 31, the jaws of which are pointed to have frictional engagement with the rod or wire R. The other set of cams or pieces secured to the cam drum 20 operates upon a pin extending from a slide 22 which is connected by an arm to a groove in an operating cam 25.

As shown most clearly in Fig. he operating cam 25 engages with and operates the bell-crank levers 26, which bell-crank levers 26 engage with the end of the clutch operating bushing 27.

As shown most clearly in Fig. 3, the clutch operating bushing 27 is provided at its end with a split-j aw clutch piece 23 having a conical end engaging a conical clamping collar 29 which is fastened in the end of the spindle 10 by a threaded cap 30.

In the operation of the parts as thus far described, the feed bushing is first moved back to secure a frictional hold upon a new section of wire, the spindle clutch is relaxed, a new length of wire is fed forward througl'r the head stock spindle, and then the clutch is again fastened to turn or rotate the wire so that it may be operated upon by successive tools.

As shown in Fig. 1, four tools are mounted. in a transversely movable slide 32. The transversely movable slide is normally held in position by a locking pin which is automatically shifted to bring the tools successively in line with the head stock spindle. The connections for withdrawing the locking pin and for shifting the tool slide are shown most clearly in Figs. 9 and 10.

As shown in Fig. 9, the taper-pointed locking pin is connected to and operated by a spring pressed lever 33. The end of the spring pressed lever 33 is arranged to be acted upon by a cam or enlargement which may be secured upon a cam wheel 34 fastened upon the cam shaft 13.

As shown in Fig. 10, the tool slide 32 is provided with a rack 35, which meshes with a gear 36. Turning with the gear 36 is a small gear which engages with and is operated by segment 37. Secured on the shaft which carries the segment 37 is an arm 38 which extends back in position to be operated upon by cams or pieces secured on the cam-wheel or drum 39 on the cam-shaft 13.

In the operation of the parts illustrated in Figs. 9 and 10 the locking pin is firstwithdrawn by the cam connections referred to, the slide is then shifted transversely to present the next tool in sequence in line with the head stock spindle, and the locking pin is then released and allowed to again move up to lock the tool slide in place until the next succeeding operation.

As shown most clearly in Fig. 2, each of the tools T is mounted on a longitudinal movable spindle 41, and threaded into the end of each spindle 41 is a regulating screw 42 which is clamped in its adjusted position by a check nut 43. The spindle 41 of each tool .is normally held back away from the work by a spring 44. Engaging the heads of the screw 42 of each tool spindle as successively brought into place is an operating piece 83 carried by a retracted slide 45, which is normally held back by a spring 46. Meshing with and engaging a rack on the under side of the slide 45 is a sector 47. The connections for turning the sector 47 to successively feed forward the tools as they are brought into position are most clearly illustrated in Figs. 8 and 11. As shown in these figures, the sector 47 is fastened upon a shaft 48, and secured upon the end of the shaft 48 is a collar 49 extending down from which is a slotted arm. Adjustably secured in this slotted arm is an operating pin or bolt 50 which extends out into a position to be 0 era-ted upon by earns or pieces secured upon t e cam wheel or drum 51, which is fastened upon the camshaft 13. I regard this construction as roviding a particularly simple and ellicient means for adjusting the operative strokes of the tools, as it not only enables ine to secure perfect and inde endent adjustments of the operations of in ividual tools by employing proper shaped cam-pieces on the cam drum or wheel 51, and by the adjustment of the end screws 42 which are threaded into the ends of the tool spindles, but in addition to this the adjustable pin 50 permits a single adjustment to change the operation of the entire series of tools. For example, if a longer screw thread is desired, it is simply necessary to raise the adjustable pin 50 to a position higher up in its slot, while on. the other hand, the machine can be adjusted for shorter screws by setting the in 50 to a position lower down in its slotter, arm.

I will next describe the train of operating devices which permit me to back the threading die off from a completed screw thread without stopping the head stock spindle or changing its direction of rotation. These devices are most clearly illustrated in Figs. 1 and '2, and the details of the die spindle are most clearly illustrated in the fifth sheet of drawings. As shown in Fig. l, a gear is secured to and turns with the high speed driving pulley l2. Meshing with and driven from the gear 55 is a smaller gear or pinion 56 secured on a shaft which is connected by a universal joint, indicated at 57, with an inclined shaft having sections which fit telescopically together. The inclined telescopic shaft is connected by a universal joint, indicated at 58, to a stud or shaft carrying a gear 59, which, as illustrated in Fig. 2, meshes with and drives a gear 60 upon the die spindle.

Referring now to the fifth sheet of drawings for a detail description of the die spindle and the manner .in which a rotation is imparted to the die in the same direction, but at higher speeds than the head stock spindle, it will be seen that the die spindle comprises a rotating or turning section (51., splined on to which is the gear (30. Fitting telescopirailly into the end of the rotating spindle section 61 is a non-rotating or sliding section 62 having a key-way 63 for preventing it from turning in its bearings in the tool slide 32. The rotating spindle section 61 and the non-rotating spindle section (52 are connected together by a pin 64. At its forward end the nonrotating spindle section 62 is provided with pins or projections 68. Fitting inside the spindle sections 61 and 6'2 is a rod or spindle 65 having at its forward end a die-holder 66. Extending back from the die-holder 66 are pins 67 which are arranged to engage with and bear upon the pins 68 to prevent the dieholder from rotating so long as the spindle is being fed forward to cut the thread. At its rear end, the spindle 65 is provided with a pin or projection which is arranged to be engaged with and turned by a clutch linger 71 extending from a ring 172 which is fastened in place in the rotating spindle section 61 by screws 173. Coiled on the spindle 65 is a light spring 69 for holding the parts in the normal position illustrated in Fig. 12.

Considering now the operation which takes place after the threading spindle has been fed forward by the tool feeding devices, the desired distance to cut the required length of screw thread, it will be seen that when the threading spindle is pulled away from the screw, the engagement of the threading die with the screw which has just been formed will prevent the spindle 65 from being drawn back so that in the first place the pins 68 and 67 will be moved out of engagement, and the pin 70 will be drawn into engagemci'it with the rotating clutch linger 71 which is now turning with the rotating spindle section bl, and the die will now be rotated in the same direction as the head stock spindle, but at a higher speed, so that the die will be backed oil from the completed screw thread. As soon as the die is freed from the completed screw thread, the spring 69 will throw the parts back to position illustrated in Fig. 12. I regard this train of operating mechanism for backing off the die from a completed screw thread as an especially ellicicnt con struction, as it operates without the reversal of the machine as a whole, andthe use of the construction avoids all and wear due to reversals.

The connections for throwing the machine from the low speed to the high speed, and vice versa, are illustrated most clearly in Figs. 1 and 2.

As shown in Fig. 1, 52 designates a slide, extending from which is a pin which can be engaged and operated by cams or pieces secured to the cam-wheel or drum 53 mounted on the cam-shaft 13. The slide 52 is connected by an arm to the ordinary double ended clutch operating piece 54, which piece 54 throws in friction clutch connections be tween the head stock spindle 10 and the driving pulleys 11 and 12. The details of the friction clutches employed for the low. speed pulley l1 and the high speed pulley 12 need not be herein shown and described, as I have employed an ordinary form of friction clutch for this purpose. The final operation in completing a screw upon a screw machine constructed according to my invention is cutting oil the screw from the end of the rod or wire. The cutting oil devices for this purpose are most clearly illustrated in Figs. 5, 6 and 7.

As shown in Fig. 5, 72 and 73 designate transversely movable slides carrying the ordinary cut oil tools for severing the screws from the rod. The slide 72 is provided with a rack 74 which, as is mostly clearly illustrated in Fig. 6, meshes with a sector 75. Extending from the sector 75 is an arm 76, j ournaled on which is a roller, which may be engaged and operated upon by cams or pieces secured on one face of the cam-wheel 77 on the cam shaft 13. The slide 7 3 is provided with a rack 7 8 which, as is most clearly illustrated in Fig. 7, meshes with a sector 7 9 having an extended arm 80, journaled on which is a roller which may be engaged and operated by pieces or cams secured upon the opposite side of the cam wheel or drum 77 from the pieces or cam which operate the sector 75 before referred to. By means of this construction, the two cut oil tools will be simultaneously moved toward each other to cut a completed screw from the end of the wire.

One of the cutting tools may be used to properly shape or chamter the head of the screw while the other cutting off tool will be used to actually sever the screw from the stock.

A special advantage in a screw machine constructed according to my invention is due to the fact that the direction of rotation of the main spindle is never changed and on this account the cutting of? tools may be so timed or brought into action that they will be actively cutting into the stock at the same time that the die is being backed oil from a completed screw thread and I regard this as of especial importance as no time is I wasted in the operation of the machine in th backward rotations of the spindle during 1 y l l l l l i l i l l i which active work cannot' be performed in fashioning a screw.

On the cam-wheels or drums 20, 58, 39 and 51, I have indicated diagrammatically the location of the operating-pieces or cams, but it is to be understood that this illustration is intended to be diagrammatic, and does not necessarily show either the correct shape or the exact position to which the cam-pieces should be adjusted. I

The several successive operations in a screw machine constructed according to my invention have been so fully described in setting forth the details of the several arts that a description of the operation or the machine as a Whole is believed to be unnecessary.

I am aware that numerous changes may be made in practicing my invention by those who are skilled in the art. For example, while I have shown my invention applied to a completely automatic machine inwhich an automatic cycle is obtained, yet I am aware that certain features of my invention may be used in other styles of machines which may not be completely automatic in nature. 'ihat is to say, certain features of my invention may be used in different classes of machines, and in combinationswith different mechanisms. I do not wish, therefore, to be limited to the particular machine which I have herein shown and described, but

What I do claim and desire to secure by Letters Patent of the United States is 1. In a machine of the class described, the combination of a head stock spindle, a transversely movable slide having a number of tools mounted therein, a locking pin, a springpressed lever normally raising said locking pin into engagement with any of a number of sockets to hold the slide in adjusted positions, a rack on the slide, a gear meshing therewith, a sector connected to operate the gear, a cam-shaft, and cam-wheels or drums mounted thereon for first releasing the springpressed lever to unlock the slide and to then shift the sector to move the slide to different positions to bring successive tools in line with the head stock spindle.

2. In a machine of the class described, the combination of a head stock spindle, a transversely movable slide, a number of tools mounted in said slide, a connecting screw threaded into the spindle of each tool, a check-nut holding each connecting screw in adjusted position, a spring for restoring each tool spindle to normal position, an operating piece having a groove for receiving the head of the connecting screw of each spindle that is moved into position, a spring normally retracting the operating piece, and means for advancing the operating piece to feed forward the successive tools.

3. In a machine 01 the class described, the

, tools mounted in said combination of a head stock spindle, a numa single adjustment will change the operative ber of tools Which are brought into line with effect of all the tools.

the head stock spindle, an operating piece for successively advancing the tools brought into line with the head stock spindle, a rack and segment for the operating piece, a cam shaft, a cam Wheel or drum, an arm turning with the segment and having a pin to be engaged by the cams or pieces on the cam Wheel, said pin being adjustable whereby a single adjustment will change the operative effect of all the tools.

4. In a machine of the class described, the combination of a head stock spindle, a slide, slide, means for moving the slide to bring successive tools into line with the. head stock spindle, an operating piece, a rack and sector therefor, a cam-shaft, a camwheel or drum on the camshaft, a slotted arm turning with the sector, and a pin to be engaged by the cams on the drum, said pin being adjustable in the slotted arm, whereby l l l 5. In a machine of the class described, the combination of a main spindle, means for automatically presenting a tool and a threading die in position to co-operate therewith, driving connections, means for automatically connecting the main spindle with the driving connections to be turned at a high speed during the operation of the tool and to be turned at a low speed in the same direction during the operation ol" the threading die, and means for rotating the threading die 1 to withdraw the same from the screw when the spindle is on the low speed.

In testimony whereof I have hereunto set my hand, in the presence ol two subscribing witnesses.

\YILLIAM ll. GATES.

W'itnesses: A

E. F. TRASK, A. C. \Vmcnr. 

